Re: [Lcd4linux-devel] Working I2C was commited minutes ago

[Luis C. <lfc...@lf...>]

Michael Reinelt wrote:

>Hi alltogether,
>
>  
>
>>Since me and Paul have been busy making this I2C sucker work for all of
>>us (yes, that includes Michael).
>>    
>>
>Works here! (I'm *that* happy :-) At least it compiles, I don't have any
>I2C-display around...
>
>Thanks for the good work!
>  
>
Finally!!!

>  
>
>>p.s. the python errors are still present, i made NO attempt to fix it,
>>as have no use for that...
>>    
>>
>I'm going to introduce a '--with-python' switch, which is disabled by
>default, so it won't disturb. As soon as this is fixed, I want to
>release 0.10
>
>  
>
Yes, that would be great.

>There are some compiler warnings (about unused arguments) which should
>be easy to clean up.
>
>  
>
Well, we are using the HD44780 framework but we no longer use the 
'delay' argument.
We may setup something that would take care of that. It is cosmetic only :)

>Another question: The current i2c code uses a 'real' i2c bus (which I
>don't have in my notebook, at least I cannot connect anything to it).
>I've seen in serdisplib that it's possible to 'emulate' a i2c bus on the
>serial port; and I got a (very strange) display from Pollin yesterday,
>which is also driven by i2c, and their sample program use the parallel
>port for i2c emulation....
>
>Should we add support for it?
>
>  
>
Well, we do use a real i2c bus for the moment.

The paralell port can be used as an emulated i2c, but code would have to 
be written, and our current framework is not ready for that.
It may become similar to the HD44780 with all the quirky modes (4bit, 
8bit, ppdev, pure paralell...).

For my embedded board, i'm also thinking to add temperature reading, as 
the sensor is also present in the other I2C bus. And no, i will not use 
lm_sensors for that. The device is not supported and the whole 
lm_sensors is kinda bloated for what I need. To give you an idea, 
reading the temperature is a 6 liner .
---------------------
    i2c_device = open("/dev/i2c-1",O_RDWR);
    ioctl(i2c_device,I2C_SLAVE, (0x90>>1) );
    temp = i2c_smbus_read_word_data(i2c_device, 0);
    temp = ((((temp && 0x00FF)<< 9) + (temp >> 8)) >> 3) / 2;
    printf("temperature: %i \n",temp);
    close(i2c_device);
---------------------

>bye, Michael
>
>  
>
We are also planning to make another mode for this I2C driver, which 
would use two PCF8574 I2C I/O extenders, in order to provide an 8 bit 
interface to the LCD display, plus a small keyboard. Thus, one of the 
things we are curious about is how are you going to implement keyboard 
support to LCD4Linux. Our keyboard will probably be very simple, 4 or 6 
keys.

Luis Correia